The correct option is D They are cells that contain multiple sets of chromosomes and not held together at a single point.
Polyploid cells are those containing more than two paired (homologous) sets of chromosomes.
Organs containing cells with polytene chromosomes are, as a rule, involved in an intense functions, like for example the salivary glands of Drosophila melanogaster. Polytene chromosomes are oversized chromosomes which have developed from standard chromosomes and all the arms of the chromosome are held together at a single point.